Updated the CONTRIBUTING.md Testing section to cover jest and vitest

CONTRIBUTING.md

@@ -17,6 +17,9 @@ If you are new to contributing to open source, please read the Open Source Guide
     - [Branching Strategy](#branching-strategy)
     - [Conflict Resolution](#conflict-resolution)
   - [Contributing Code](#contributing-code)
+    - [Jest Testing](#jest-testing)
+    - [Vitest Testing](#vitest-testing)
+    - [Combined testing and coverage](#combined-testing-and-coverage)
 - [Internships](#internships)
 - [Community](#community)
 
@@ -98,27 +101,58 @@ The process of proposing a change to Talawa Admin can be summarized as:
       1. Pull requests that don't meet the minimum test coverage levels will not be accepted. This may mean that you will have to create tests for code you did not write. You can decide which part of the code base needs additional tests if this happens to you.
 
    2. **_Testing_:**
-
-      1. Test using this set of commands:
-
+      #### Jest Testing 
+      1. Running a single test:
+         ```
+         npm run test path/to/test/file
+         ```
+      2. Running all tests:
+         ```
+         npm run test --watchAll=false
+         ```
+      3. Viewing the code coverage of a single test file:
+         ```
+         npm run test --watchAll=false --coverage /path/to/test/file
+         ```
+      4. Viewing the code coverage of all test files:
          ```
-         npm install
          npm run test --watchAll=false --coverage
          ```
-
-      2. Debug tests in browser
-
+      5. Debug tests in browser
          You can see the output of failing tests in broswer by running `jest-preview` package before running your tests
-
          ```
-         npm install
          npm run jest-preview
          npm run test --watchAll=false --coverage
          ```
-
          You don't need to re-run the `npm run jest-preview` command each time, simply run the `npm run test` command if the Jest Preview server is already running in the background, it'll automatically detect any failing tests and show the preview at `http://localhost:3336` as shown in this screenshot -
 
          ![Debugging Test Demo](./public/images/jest-preview.webp)
+      #### Vitest Testing
+      1. Running a single test:
+         ```
+         npm run test:vitest /path/to/test/file
+         ```
+      2. Running all tests:
+         ```
+         npm run test:vitest
+         ```
+      3. Viewing the code coverage of a single test file:
+         ```
+         npm run test:vitest:coverage /path/to/test/file
+         ```
+      4. Viewing the code coverage of all test files:
+         ```
+         npm run test:vitest:coverage
+         ```
+      #### Combined testing and coverage
+      1. Running all tests:
+         ```
+         npm run test && npm run test:vitest
+         ```
+      2. Viewing combined code coverage:
+         ```
+         npm run test --watchAll=false --coverage && npm run test:vitest:coverage
+         ```
 
    3. **_Test Code Coverage_:**